1. Field of the Invention
This invention relates to an ink jet recording head where piezoelectric vibrators expand or shrink a pressure generation chamber to generate ink drops, and more particularly to a structure of a piezoelectric vibrator unit of such an ink jet recording head.
2. Description of the Related Art
An ink jet recording head using piezoelectric vibrators having a nozzle plate formed with nozzle openings, a spacer for separating a pressure generation chamber, an ink supply port, a reservoir, and a vibration plate deformed by the piezoelectric vibrators to expand or shrink the pressure generation chamber is well known. The piezoelectric vibrators are oscillated based on a print signal to shrink or expand the pressure generation chamber, and thereby suck ink into the pressure generation chamber and eject ink drops therefrom consecutively.
In such an ink jet recording head, the area where piezoelectric vibrators abut a vibration plate can be made extremely small by using piezoelectric vibrators in a vertical vibration mode formed by laminating electrode material and piezoelectric material. With such a construction, a recording head having a resolution of 180 dpi or more can be provided.
A piezoelectric vibrator unit having piezoelectric vibrators each being, for example, 5 mm long, 70 .mu.m wide, and 0.5 mm thick disposed on a piezoelectric vibrator support plate with a 0.14-mm pitch is used in such a high resolution recording head. To manufacture the piezoelectric vibrator units, a piezoelectric vibration plate formed by laminating alternate layers of piezoelectric material and electrode material and sintering them is formed with electrodes on one surface and cut like strips with a dicing saw, a wire saw, or the like with a predetermined pitch, such as 0.14 mm, with one end of the electrode face fixed to a base in a cantilever fashion.
Since the electrodes formed on the base must be separated for each piezoelectric vibrator the cut depth must extend at least to the piezoelectric vibrator support plate. Thus, material having excellent cutting properties, such as glass or piezoelectric material, is used for the piezoelectric vibrator support plate to avoid added resistance to cutting when the piezoelectric vibration plate is cut, thereby preventing the piezoelectric vibrators from being broken imperfectly formed.
According to this method, cutter vibration and shock can be prevented and the manufacturing yield of the vibrator units can be improved. On the other hand, materials having excellent cutting properties are low in rigidity. Thus when such devices receive a reaction force of the piezoelectric vibrators to which a drive signal is applied for jetting ink drops, they are easily distorted and the piezoelectric vibrators located nearby are displaced axially, causing ink mist ejection, i.e. undesired ink ejection, or crosstalk to occur.